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BackgroundThe autoimmune disease lupus erythematosus (lupus) is characterized by photosensitivity, where even ambient ultraviolet radiation (UVR) exposure inflames skin. Beneficial effects of anifrolumab (anti-interferon α/breceptor (anti-IFNAR)) on lupus skin disease support a pathogenic role for IFN-I, but mechanistic understanding is limited. We have shown that Langerhans cell (LC) dysfunction contributes to photosensitivity. Healthy LCs act via a disintegrin and metalloprotease 17 (ADAM17) to release epidermal growth factor receptor (EGFR) ligands that limit UVR-induced keratinocyte apoptosis and photosensitivity. However, LC ADAM17 activity is reduced in non-lesional lupus model skin, and data point to reduced LC-mediated protection in human lupus. Here, we asked about the role of the IFN-rich lupus skin environment in LC dysfunction and the implications of this regulation for photosensitivity.MethodsGene expression patterns in non-lesional skin from human lupus and multiple murine models were examined. We used MRL/lpr, B6.Sle1yaa, and imiquimod models of lupus inin vivostudies to assess the role of IFN-I in LC ADAM17 dysfunction and photosensitivity.ResultsWe show a shared IFN-rich environment in non-lesional skin across human and murine model systems, that IFN-I inhibits LC ADAM17 activity, and that anti-IFNAR in lupus models restores LC ADAM17 function and reduces photosensitivity in EGFR and LC ADAM17-dependent manners. Reactive oxygen species (ROS) can mediate ADAM17 activity, and we show reduced LC ROS expression in lupus models that is restored by anti-IFNAR.ConclusionsOur findings suggest that IFN-I promotes photosensitivity by causing LC ADAM17 dysfunction and that anifrolumab ameliorates lupus skin disease at least in part by restoring LC function. This work provides insight into IFN-I-mediated disease mechanisms, LC regulation, and a mechanism of action for anifrolumab in lupus.

Background/objective The importance of patient-reported outcomes, like the Patient-Reported Outcomes Measurement Information System (PROMIS) measures, is increasingly recognized both in clinical care and in research. While "short forms" have been studied in juvenile idiopathic arthritis (JIA), study of PROMIS computer adaptive tests (CATs) in JIA is limited. This cross-sectional study evaluates whether PROMIS CATs correlate with disease activity in patients with JIA. Methods A convenience sample of patients with JIA (N = 44) was recruited from a single center. Patients and parents completed pediatric and parent proxy PROMIS CATs. Disease activity was evaluated using the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71) and the Childhood Health Assessment Questionnaire (CHAQ). Correlation of the CAT T scores with disease activity was assessed using Spearman correlation coefficients. Results Forty-four of 80 eligible subjects (29 patients and 15 parents) completed all or some PROMIS CATs. Pain interference and mobility CATs correlated moderately with JADAS-71. Nearly all correlations with the JADAS-71 were weakened when the patient global was removed. Pain interference, mobility, and fatigue were strongly correlated with the CHAQ. Among parent proxy CATs, only mobility and depressive symptoms correlated strongly with the CHAQ. Conclusions Only pain interference and mobility PROMIS CATs showed strong correlation with standard disease activity measures in JIA, and nearly all correlations were weakened when the patient global was removed. Correlations of the CATs with the CHAQ were stronger than correlations with the JADAS-71, indicating that although the CHAQ is no longer routinely used it may be a better measure of health-related quality of life in routine clinical care.

Juvenile-onset systemic sclerosis (jSSc) is a rare and severe autoimmune disease with associated life-threatening organ inflammation and evidence of fibrosis. The organ manifestations of jSSc resemble adult SSc, but with better outcomes and survival. The etiology of jSSc appears to reflect adult-onset SSc, with similar inflammatory mediators and autoantibodies, but with a significant population of children with uncharacterized anti-nuclear antibodies. The genetics of patients with jSSc differ from women with SSc, resembling instead the genes of adult males with SSc, with additional HLA genes uniquely associated with childhood-onset disease. Current treatments are aimed at inhibiting the inflammatory aspect of disease, but important mechanisms of fibrosis regulated by dermal white adipose tissue dendritic cells may provide an avenue for targeting and potentially reversing the fibrotic stage.